Hello! Susten 200 contains progesterone which is a natural sex hormone. It is indicated in abnormal uterine bleeding, amenorrhea (missing periods), preventing preterm childbirth, infertility (to support the inner lining of uterus) and to support pregnancy in early stages, especially in patients with recurrent pregnancy loss. Progesterone belongs to category B of FDA pregnancy categories, which by definition contain all drugs that in animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women . It may have different side effects, the mos common are headache, abdominal pain, breast sore, dizziness, depression, weakness. In your question isn t clear why the doctor prescribed the drug, if there have been miscarrieges, or it was a medical assisted pregnancy or other conditions are present. I would suggest you to ask your wife ob/gyn, and if it is difficult or you are still unclear i woud be glad to help you further with your concerns. Kind regards